Our company produces COM controls. For partners to be able to use Visual Studio .NET, we also deliver Primary Interop Assemblies (PIAs).

In testhouse we have limited vstudio 6.0/c++/mfc skills and for a (long!) time used VS.NET03/C# (we have two MCPs of 70-316) for several test/automation tools.

Now a discussion has started, that using the Primary Interop assemblies in our testtools, isn't sufficient for test coverage.

What's your opinion? And (more important What would be good arguments I can give people higher up the food chain, so those grim creatures won't force me doing MFC appz (again!)...?